﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.Security.Cryptography;
using System.IO;

namespace DelonixRegiaHMSys.UI.Models
{
    public class Encryption
    {
        string _QueryStringKey = "abcdefgh"; //URLEncrptionKey

        public Encryption()
        {


        }

        public string EncryptQueryString(string QueryString)
        {
            return Encrypt(QueryString, _QueryStringKey);
        }


        public string DecryptQueryString(string QueryString)
        {
            return Decrypt(QueryString, _QueryStringKey);
        }




        public string Encrypt(string pToEncrypt, string sKey)
        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = Encoding.GetEncoding("UTF-8").GetBytes(pToEncrypt);

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

            cs.Write(inputByteArray, 0, inputByteArray.Length);

            cs.FlushFinalBlock();

            StringBuilder ret = new StringBuilder();

            foreach (byte b in ms.ToArray())
            {

                ret.AppendFormat("{0:X2}", b);

            }

            ret.ToString();

            return ret.ToString();

        }


        public string Decrypt(string pToDecrypt, string sKey)
        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = new byte[pToDecrypt.Length / 2];

            for (int x = 0; x < pToDecrypt.Length / 2; x++)
            {

                int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));

                inputByteArray[x] = (byte)i;

            }

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);

            cs.Write(inputByteArray, 0, inputByteArray.Length);

            cs.FlushFinalBlock();

            StringBuilder ret = new StringBuilder();

            return System.Text.Encoding.Default.GetString(ms.ToArray());

        }


        public bool ValidateString(string EnString, string FoString, int Mode)
        {
            switch (Mode)
            {
                default:
                case 1:
                    if (Decrypt(EnString, _QueryStringKey) == FoString.ToString())
                    {
                        return true;
                    }

                    else
                    {
                        return false;
                    }
            }
        }
    }
}